import java.math.BigDecimal;
import java.math.BigInteger;


public class P2 {
	public static void main(String[] args) {
		BigInteger x = new BigInteger("1");
		BigInteger y = new BigInteger("2");
		BigInteger b2 = new BigInteger("2");
		BigInteger b0 = new BigInteger("0");
		
		BigInteger sum = new BigInteger("2");
		
		for (int i = 3; true; i++) {
			BigInteger temp = y;
			y = x.add(y);
			x = temp;
			
			if (y.mod(b2).equals(b0)) { 
				sum = sum.add(y);
			}	
			
			if (i%100000 == 0) {
				System.out.println(i);
			}
		}	
	}
}
